The Question:

I am trying to find out the author of "Mary Had A Little Lamb"
for my daughter's school project. Can you please help?

The Answer:

Sure. The poem was originally called "Mary's Lamb" and it was
written by Sarah Josepha
Hale. It first appeared in a book of verses called "Poems For
Our Children" in 1830.

After the poem was published, a woman named Mary Sawyer, who as
a young girl went to school at Redstone School in Sterling, Mass.,
claimed she was the "Mary" in the poem. In 1817 she did have a lamb
follow her to school and she remembered being handed a poem about the
event by 12-year-old John Rhoulstone. There is no evidence of whether
or not Hale ever saw that poem.